Streaking on 120 C41 Film in Jobo

robskips · Sep 22, 2019

I'm having this issue of very faint streaking on my negatives developed in a CPP2 with lift, using 1500 series drums and reels. The streaking is almost non-existent except on very underexposed frames, but it's visible on the negatives on the light table.

I use Kodak Flexicolor dev and bleach and Fuji C41 Fix. My process is 3 minute Pre-wash, Dev, RA Bleach, 3 min wash, Fuji Fix, 5 minute wash, Final rinse off the reels in a separate container. Washes are 30 second intervals. Dev and Bleach are replenished to sepc / manually aerated. Fix is one-shot. I'm running anywhere from one roll to six rolls at a time in different sized tanks. I've tried no prewash and it didn't seem to make a difference. I was also getting foaming developer and surging on the negatives when I didn't prewash. I do add a couple drops of LFN low-foam wetting agent to the developer as suggested elsewhere.

I'm posting a scan of an unexposed frame as an example of what I'm talking about. Don't mind the banding. That's a scanning artifact.

mshchem · Sep 22, 2019

I would look at the Kodak instructions for using Flexicolor with a Jobo. They do not recommend, pre wash or replenishment. They even recommend that the bleach be used one shot. I will admit that I've been a prewash guy over the years, but I now follow the instructions.
I can't bring myself to toss the bleach after one use, I replenish that.
I use the Kodak Final Rinse, I leave the film on the reels and soak for about 30 seconds then shake the reel to remove the excess rinse, hang and dry without heat.

I remember a high school buddy that informed me that the rainbow on soap film was a "thin film chromatic aberration" he was a honors student so who was I to argue.

Distilled water for final rinse, don't heat to dry and follow the instructions, MHO.

robskips · Sep 22, 2019

So you think it might be pre-wash related? I have read Kodak's manuals pretty thoroughly. I do know their recommendations, but I see so many people recommend it to prevent problems like this too.

pentaxuser · Sep 22, 2019

Can we take it that your process hasn't changed and that the streaking has always been there or is this a new phenomenon that only arose recently? If so how many films ago and if so what might have changed?

pentaxuser

mshchem · Sep 22, 2019

robskips said:
So you think it might be pre-wash related? I have read Kodak's manuals pretty thoroughly. I do know their recommendations, but I see so many people recommend it to prevent problems like this too.

I think it's not pre wash related. The only issue with pre wash is it dilutes the developer (and actually gets everything up to temperature ). I would look at the final rinse step, you could be transferring skin oil, or something like that. I would rather replace a gunked up reel, than handle a long strip of film. Do the final rinse off the machine, on the reel, clip onto the film with a stainless steel film clip and pull the film off the reel. I don't touch with my fingers until the film is dry.

robskips · Sep 22, 2019

I can't remember when I started noticing it, but it was recent. That's why I'm having trouble tracking it down. I develop a lot of film, and I've changed a lot of stuff recently after I started getting the foaming developer and surge marks. The main things I've changed are the LFN agent and the pre-wash. I'm thinking it has something to do with either of those. I wonder if too much LFN is in the developer, or if my pre-wash is causing the dev to not evenly distribute across the film.

robskips · Sep 22, 2019

mshchem said:
I would look at the final rinse step, you could be transferring skin oil, or something like that. I would rather replace a gunked up reel, than handle a long strip of film. Do the final rinse off the machine, on the reel, clip onto the film with a stainless steel film clip and pull the film off the reel. I don't touch with my fingers until the film is dry.

I'll take a look at my rinse process, but it doesn't look like water marks on the negative. I've definitely dealt with those in the past. I only touch the film with gloves, never with my hands.

mshchem · Sep 22, 2019

robskips said:
I can't remember when I started noticing it, but it was recent. That's why I'm having trouble tracking it down. I develop a lot of film, and I've changed a lot of stuff recently after I started getting the foaming developer and surge marks. The main things I've changed are the LFN agent and the pre-wash. I'm thinking it has something to do with either of those. I wonder if too much LFN is in the developer, or if my pre-wash is causing the dev to not evenly distribute across the film.

Make up fresh developer. Forget the LFN. Good place to start. Do the streaks show up in a scan or print?

robskips · Sep 22, 2019

mshchem said:
Make up fresh developer. Forget the LFN. Good place to start. Do the streaks show up in a scan or print?

I'll give it a shot. They show up in very underexposed shadows, mostly as green shifts.

mshchem · Sep 22, 2019

robskips said:
I'll give it a shot. They show up in very underexposed shadows, mostly as green shifts.

Let's see if some real expert chimes in. The green means something. I suspect it's related to Jobo/replenishment issue. I love my Jobo stuff but it aerates the heck out of the solutions.

Photo Engineer · Sep 22, 2019

Looks like carryover of developer into bleach. It is not a prewet problem.

Try a 30" stop after the developer. Use 2 - 5% Acetic Acid.

PE

robskips · Sep 22, 2019

Photo Engineer said:
Try a 30" stop after the developer. Use 2 - 5% Acetic Acid.
PE

PE, thanks! I was hoping you would chime in. So I can just dilute some Kodak Indicator Stop down to 2-5%?

Photo Engineer · Sep 22, 2019

I believe that that is the usual working strength anyhow.

The indicator is harmless to the film.

PE

robskips · Sep 22, 2019

And it won't have an effect on the bleach activity?

Photo Engineer · Sep 22, 2019

No, but if you are worried, add a slight 30" rinse of water after the stop.

PE

koraks · Sep 23, 2019

Store bought cleaning vinegar is about 7-8%, a little dash into some water makes a perfectly usable one shot stop bath.
Despite that it may not be the issue I'd skip the wetting agent in the developer. I personally don't pre rinse but just do a dry warm (hook the tank up to the job and have it rotate without any liquid for a few minutes). Works a treat this way. I do use a stop and a rinse after stop, two rinses after bleach.

Bikerider · Sep 23, 2019

All C41 developers state 3mins 15 seconds @ 38Degrees C. Anything less and you risk uneven development. What are you using? The sequence I use is after 3.15 developer, 1 minute plain water rinse and the 7 minutes bleach, another 1 minute water rinse and 7 minutes fixer and end up with 6 x 30 seconds wash and 1 minute stabiliser. The rotary motion of the drum is also likely to give uneven development on the edges (My experience) if the speed is on the high setting so I always set it to run the development stage at the slower setting. Some may say extending the bleach and fix times is wrong and will 'over-cook' things, but that is very definitely not what I have found. I have negs up to 30 years old that still print reasonably well and I didn't even use the stabiliser then.

Some may say the speed must be on the high setting, but why? If we do not use a JOBO we do not offer constant hand development do we?. I use the higher speed for the bleach and fix to give a more vigorous action, likewise the final rinse - except the stabiliser which is always on the slower setting

koraks · Sep 23, 2019

Re speed setting on the Jobo: some people experience uneven development at either the high or the low setting, so try and choose which gives the best results. The unevenness caused by problems with fluid dynamics as a result of rotation speed look different from what we see in this thread, so I think that's not the cause. When experiencing problems with high or low density at the edges of the film or 'wagon tracks' along the length of the film, a different speed setting may alleviate the problem.

Photo Engineer · Sep 23, 2019

I missed that. No wetting agent in any developer ever!

PE

robskips · Sep 26, 2019

Well, the stop bath cured the problem. Thanks, all.

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